21120210002221 has 12 divisors (see below), whose sum is σ = 23444625567132. Its totient is φ = 19010090000000.

The previous prime is 21120210002201. The next prime is 21120210002251. The reversal of 21120210002221 is 12220001202112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19110580549225 + 2009629452996 = 4371565^2 + 1417614^2 .

It is not a de Polignac number, because 21120210002221 - 2¹³ = 21120209994029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21120210002195 and 21120210002204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120210002201) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 864082780 + ... + 864107221.

It is an arithmetic number, because the mean of its divisors is an integer number (1953718797261).

Almost surely, 2^{21120210002221} is an apocalyptic number.

It is an amenable number.

21120210002221 is a deficient number, since it is larger than the sum of its proper divisors (2324415564911).

21120210002221 is a wasteful number, since it uses less digits than its factorization.

21120210002221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1728190124 (or 1728190113 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21120210002221 its reverse (12220001202112), we get a palindrome (33340211204333).

The spelling of 21120210002221 in words is "twenty-one trillion, one hundred twenty billion, two hundred ten million, two thousand, two hundred twenty-one".